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Texas Instruments LM3432SQX/NOPB
- Part No.:
- LM3432SQX/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 24-WFQFN Exposed Pad
- Datasheet:
-
LM3432SQX/NOPB.pdf
- Description:
- IC LED DRV RGLTR PWM 40MA 24WQFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,220
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Product details
Overview
LM3432SQX/NOPB from Texas Instruments is a 6-channel high-voltage LED current regulator IC for LCD backlighting, delivering ±2.0% current matching at 40mA per channel, supporting up to 80V IOUT voltage, and enabling digital PWM or analog dimming control with 4000:1 dimming ratio at 500Hz.
For engineers reviewing the LM3432SQX/NOPB datasheet, LM3432SQX/NOPB pinout, LM3432SQX/NOPB application, or LM3432SQX/NOPB equivalent, this device serves as a thermally enhanced WQFN-24 current sink for multi-string LED backlight systems requiring precise string regulation, fault signaling (short/over-temperature), and Dynamic Headroom Control integration with LM3430 boost controllers.
Technical Context
The LM3432SQX/NOPB integrates six independent current-sink channels with bandgap-referenced IREF-based programming (15–40mA), internal 5V linear regulator (VCC) with UVLO (4.15V rising), and dual-dimming mode selection via MODE pin (ground = PWM, capacitor-to-GND = analog). It supports fast switching (tr = 25ns typical) and phase-delayed channel toggling to minimize supply surge currents.
Its fault architecture includes open-drain FAULTb (LED short or open-LM3432 only-and over-temperature) and OTMb (over-temperature warning), both active-low. DHC functionality uses VDHC output (0.625V typical regulation at 20mA) to dynamically adjust LED supply voltage in coordination with LM3430, reducing power loss across the current sinks.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Channels | 6 independent current sinks, each adjustable 15–40mA via RIREF resistor |
| Max IOUT Voltage | 80V - enables driving long LED strings (e.g., 12× white LEDs @ ~4V each) |
| Current Matching | ±2.0% at 40mA - ensures uniform brightness across all backlight strings |
| Rise Time (tr) | 25ns typical - supports high-frequency PWM dimming without waveform distortion |
| Dimming Ratio | Up to 4000:1 at 500Hz - achieves deep black levels in LCD displays |
| Thermal Shutdown | 165°C with 20°C hysteresis - protects die during sustained overload or poor heatsinking |
| VCC Regulation | 5.0V ±0.25V, 9mA max - powers internal circuitry and supports small external loads |
Pinout & Package
LM3432SQX/NOPB is housed in a thermally enhanced 24-pin WQFN package (5mm × 4mm × 0.8mm) with exposed thermal pad (EP) connected to PGND. Pin count and layout match the LM3432B variant; the LM3432SQX/NOPB is functionally identical to LM3432 but supplied in WQFN-24 only.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Supply input | 6–40V DC input rail; withstands 42V transients - powers internal regulator and bias circuits |
| VCC | Internal LDO output | Stable 5V supply for internal logic; requires ≥680nF CVCC capacitor for stability |
| IREF | Current reference node | 1.245V bandgap reference; sets IOUT via RIREF (e.g., 54.7kΩ → 20mA) |
| IOUT1–IOUT6 | Current sink outputs | Each drives one LED string; withstands 80V; channels 5/6 can be disabled by grounding pre-power-up |
| EN | Enable control | Active-HIGH logic; pulls all outputs to high-impedance when LOW (IOUT_OFF ≤3µA) |
| MODE | Dimming mode select | Ground = digital PWM; capacitor-to-GND = analog dimming (sawtooth generation) |
| DIM | Dimming signal input | Accepts 0–5V analog voltage or 1.7V+ PWM signal - controls duty cycle of all six channels |
| FAULTb / OTMb | Fault status outputs | Open-drain, active-low signals to MCU - FAULTb indicates LED short (or open on LM3432); OTMb warns at 125°C |
| VDHC / CDHC | DHC interface | VDHC outputs regulated headroom voltage (0.625V @20mA); CDHC sets DHC loop response time via external capacitor |
| AGND / PGND | Analog & power ground | Separate ground paths reduce noise coupling; EP must connect directly to PGND for thermal performance |
Key Features
| Feature | Design Value |
|---|---|
| Dynamic Headroom Control (DHC) | Reduces LED supply voltage to minimum required headroom (e.g., 0.625V @20mA), cutting power loss in current sinks by >30% vs fixed-rail designs |
| String Current Matching | ±2.0% at 40mA ensures consistent luminance across all backlight zones - critical for edge-lit LCD uniformity |
| Dual Dimming Interface | Hardware-selectable mode (MODE pin) eliminates need for firmware reconfiguration when switching between analog voltage and PWM control |
| Fault Signaling Architecture | Dedicated FAULTb and OTMb pins provide immediate, isolated alerts to MCU - enables real-time backlight health monitoring and graceful degradation |
| Thermally Optimized WQFN-24 | θJA = 33.2°C/W enables 1.2W dissipation at TA = 85°C - supports compact, fanless LCD backlight modules |
Applications
| LCD Display Backlighting | General Lighting Modules |
|---|---|
|
Use Scenario: Driving six parallel LED strings (e.g., 12 white LEDs per string) in a 10.1″–15.6″ LCD panel with local dimming zones. IC Role / Device Role / Timing Role: 6-channel current sink regulating string current with <25ns rise time and phase-delayed switching to suppress EMI and rail droop. Use Value: Enables uniform brightness, 4000:1 contrast via deep dimming, and compatibility with TI's LM3430 boost controller for system-level efficiency optimization. |
Use Scenario: Compact LED driver board for commercial signage or architectural accent lighting with adjustable per-string current. IC Role / Device Role / Timing Role: High-voltage current regulator supporting up to 80V per string - allows flexible LED string configuration without external MOSFETs. Use Value: Reduces BOM count by integrating six matched sinks, fault reporting, and DHC interface - simplifies compliance with IEC 62368-1 safety requirements. |
| Automotive Infotainment Displays | Industrial HMI Panels |
|
Use Scenario: Backlight for TFT display in automotive cluster or center console operating across -40°C to +125°C junction range. IC Role / Device Role / Timing Role: Temperature-stable current regulator with ±2.0% matching over full range and thermal shutdown at 165°C. Use Value: Ensures consistent display luminance and reliability under thermal cycling - meets AEC-Q100 stress test requirements for Grade 2 (105°C ambient). |
Use Scenario: Ruggedized human-machine interface in factory automation equipment requiring long service life and fault diagnostics. IC Role / Device Role / Timing Role: Fault-aware LED driver providing open/short detection (LM3432) and over-temperature warning to PLC or host controller. Use Value: Enables predictive maintenance via FAULTb/OTMb logging - reduces unplanned downtime in 24/7 production environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LED current regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM3432MMX/NOPB | eHTSSOP-28 package (θJA = 29°C/W); includes all LM3432 features including LED open-fault detection | Better thermal performance in high-power layouts; larger footprint accommodates manual soldering and higher copper area | Select when PCB layout allows 28-pin package and open-fault reporting is required - LM3432SQX/NOPB lacks open-fault capability |
| TPS61165DRVR | Single-channel, 40V boost LED driver with integrated switch; no multi-string current matching or DHC interface | Designed for single-string portable displays; lacks 6-channel synchronization, fault isolation, or headroom control | Choose only for cost-sensitive, low-channel-count applications where string matching and system-level efficiency are secondary |
Compared with LM3432MMX/NOPB, LM3432SQX/NOPB trades open-fault detection and lower thermal resistance for smaller WQFN-24 footprint and lower assembly cost; versus TPS61165DRVR, it provides true multi-string regulation and DHC-driven efficiency gains unattainable with single-channel boost architectures.
Availability
LM3432SQX/NOPB is available at Aetrix Electronics and suitable for LCD display backlighting, general lighting modules, automotive infotainment displays, and industrial HMI panels requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LM3432SQX/NOPB includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management technologies, with decades of expertise in LED driver innovation and automotive-grade reliability.
The LM3432 product line was designed specifically for high-efficiency, multi-string LED backlight systems in LCD displays - emphasizing current matching, thermal robustness, and seamless integration with TI's complementary boost controllers like LM3430.
FAQ
What is the maximum LED string voltage supported by LM3432SQX/NOPB?
The LM3432SQX/NOPB supports up to 80V across each IOUT pin relative to PGND, enabling configurations with up to ~20 white LEDs (3.8–4.2V each) per string. This rating is validated per absolute maximum specifications and applies across the full operating temperature range (-40°C to +125°C junction).
Does LM3432SQX/NOPB support LED open-circuit fault detection?
No, LM3432SQX/NOPB does not support open-circuit fault detection. That feature is exclusive to the LM3432 (e.g., LM3432MMX/NOPB) and omitted in the LM3432B family, which includes LM3432SQX/NOPB. Only short-circuit and over-temperature faults trigger FAULTb assertion in LM3432SQX/NOPB.
How is LED current programmed on LM3432SQX/NOPB?
LED current is set via an external resistor (RIREF) connected between IREF pin and AGND. The relationship is IOUT ≈ 1.094 mA × (10⁶ / RIREF), where RIREF is in ohms. For example, 54.7kΩ yields ~20mA per channel. A ±1% tolerance, low-TCR resistor is recommended for stable operation across temperature.
Can LM3432SQX/NOPB be used without Dynamic Headroom Control?
Yes, LM3432SQX/NOPB operates fully without DHC: leave VDHC floating and omit CDHC capacitor. In this mode, short-fault detection remains active only if all IOUT voltages are below ~2V; above that threshold, short-fault protection disables to prevent false triggers - a key design consideration for fixed-rail systems.
What dimming interfaces does LM3432SQX/NOPB support?
LM3432SQX/NOPB supports both digital PWM and analog voltage dimming. Select mode via MODE pin: tie to GND for PWM input on DIM pin (1.7V min HIGH), or connect CMODE capacitor to GND for analog dimming (0–3V on DIM sets 0–100% duty cycle). Both modes deliver up to 4000:1 dimming ratio at 500Hz.
LM3432SQX/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 24-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- DC DC Regulator
- Topology:
- Step-Up (Boost)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 6
- Voltage - Supply (Min):
- 6V
- Voltage - Supply (Max):
- 40V
- Voltage - Output:
- 80V
- Current - Output / Channel:
- 40mA
- Frequency:
- -
- Dimming:
- Analog, PWM
- Applications:
- Backlight
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-WQFN (4x5)
LM3432SQX/NOPB FAQ
1.How can I place an order for LM3432SQX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3432SQX/NOPB on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LM3432SQX/NOPB reliable?
The price and inventory of LM3432SQX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3432SQX/NOPB is usually 5 days.
3.What payment methods are accepted for LM3432SQX/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3432SQX/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3432SQX/NOPB?
LM3432SQX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3432SQX/NOPB order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LM3432SQX/NOPB?
For technical support, including LM3432SQX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3432SQX/NOPB requirements.
6.How does Aetrix verify that LM3432SQX/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3432SQX/NOPB products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LM3432SQX/NOPB meets industry standards.
7.What is the process for return or replacement of LM3432SQX/NOPB?
All LM3432SQX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3432SQX/NOPB, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LM3432SQX/NOPB part is unused and in its original packaging.
Return procedure for LM3432SQX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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